Tau Tauri

Not to be confused with T Tauri.
Tau Tauri
Location of τ Tauri (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Taurus
Right ascension 04h 42m 14.70161s[1]
Declination 22° 57′ 24.9214″[1]
Apparent magnitude (V) 4.27[2]
Characteristics
Spectral type B3V[3] + ? + A0V–A2V[4] + A1V[5]
U−B color index -0.57[6]
B−V color index -0.14[6]
Astrometry
Radial velocity (Rv)+14.60[7] km/s
Proper motion (μ) RA: -2.89[1] mas/yr
Dec.: -21.86[1] mas/yr
Parallax (π)8.19 ± 0.88 mas[1]
Distanceapprox. 400 ly
(approx. 120 pc)
Absolute magnitude (MV)-1.15[2]
Orbit[8]
PrimaryAa
Period (P)2.956549±0.000002 d
Semi-major axis (a)≤ 0.01455 AU
Eccentricity (e)0.051±0.019
Periastron epoch (T)2,436,424.207±0.009 JD
Argument of periastron (ω)
(secondary)		126.7±21.8°
Semi-amplitude (K1)
(primary)		53.6±1.0 km/s
Details
Aa
Mass6.4[9] M☉
Luminosity1,472[10] L☉
Surface gravity (log g)2.60[11] cgs
Temperature18,700[10] K
Metallicity [Fe/H]-0.51[11] dex
Rotational velocity (v sin i)115[12] km/s
Other designations
τ Tau, 94 Tauri, BD+22°739, FK5 174, GC 5716, HD 29763, HIP 21881, HR 1497, SAO 76721, CCDM J04422+2257AB, WDS J04422+2257A, GSC 01830-02129[13]
Database references
SIMBADdata

Tau Tauri, Latinized from τ Tauri, is a quadruple star system[5] in the constellation Taurus. It is visible to the naked eye as a faint point of light with a combined apparent visual magnitude of 4.33.[14] The distance to this system is approximately about 400 light years based on parallax.[1] The system is moving further from the Earth with a heliocentric radial velocity of +14.6 km/s,[7] and it is a member of the Taurion OB association, located between Orion and Taurus.[15] It is located 0.7 degree north of the ecliptic, and thus is subject to lunar occultations.[4]

The blue-white hued primary, component Aa, is a B-type main-sequence star with a stellar classification of B3V.[3] It was found to be a close spectroscopic binary in 1903 by American astronomers Edwin B. Frost and Walter S. Adams. The pair have an orbital period of 2.96 days and eccentricity of 0.05.[8] A second companion, white-hued component Ab, has magnitude 6.97 and angular separation 0.2" from the primary in a 58-year orbit.[16][5] This is a probably A-type main-sequence star with a class of A0V–A2V.[4] The more distant component B is a type A1V star with magnitude 7.2 and separation 62.8".[5]

  1. ^ a b c d e f Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference XHIP was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Hoffleit1991 was invoked but never defined (see the help page).
  4. ^ a b c Cite error: The named reference Richichi1994 was invoked but never defined (see the help page).
  5. ^ a b c d Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Mallama2014 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Wilson1953 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference Petrie1961 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Tetzlaff2011 was invoked but never defined (see the help page).
  10. ^ a b Cite error: The named reference Hohle2010 was invoked but never defined (see the help page).
  11. ^ a b Cite error: The named reference Wu2011 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Abt2002 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference WDS was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference Buoy2015 was invoked but never defined (see the help page).
  16. ^ Cite error: The named reference Malkov2012 was invoked but never defined (see the help page).